1. Technical Field
The present invention relates to an electrostatic induction generation device and an electrostatic induction generation apparatus.
2. Related Art
In accordance with the recent environmental concerns, electrical power generation using natural energy such as electrical power generation using solar energy or wind energy has been starting to spread widely. However, both of the solar energy and the wind energy must depend on the conditions for installation, namely the environment such that the sunlight is not blocked or that the stable wind is blowing. In contrast thereto, a method of converting the environmental vibration into electrical power attracts attention. As such a method, those using electromagnetic induction or piezoelectricity can be cited, and in particular, the electrostatic method using electromagnetic induction is a technology capable of downsizing and cost reduction with a simple structure.
The principle of the electrical power generation using the electrostatic method is as follows. A substrate provided with an electret semipermanently holding surface electric charge is used as one substrate. The other substrate opposed to the one substrate is provided with an electrode. Then the substrates are moved so as to make a relative movement (displacement) to thereby vary the area of the electrode opposed to the electret. The variation in the dielectric charge caused in the electrode is taken out to thereby generate electricity (Japanese Patent No. 4,338,745 (Document 1)).
In the electrical power generation using the electrostatic method, the charge held by the electret and the dielectric charge generated on the opposed electrode cause the Coulomb force in the attracting direction to act between electrodes to thereby make the electrodes opposed to each other with a small gap have contact with each other, which hinders the relative displacement or causes displacement (behavior) in a direction different from the relative displacement direction to thereby make the efficient electrical power generation difficult. Therefore, there has been proposed an electrostatic induction generation provided with a guard and a stopper for limiting the relative displacement (WO 08/026407 brochure (Document 2)).
However, even in the device of Document 2, the contact between the guard and the electrode hinders the normal relative displacement between the electrodes to thereby make the electrical power generation unstable.